CONCEPTS FOR OFFSHORE EXPLORATION IN PACK-ICE AREAS

Détails concernant le projet

Coût total:

Contribution de l'UE:

Coordonné à/au(x)/en:

Sujet(s):

Régime de financement:

DEM - Demonstration contracts

Objectif

The ultimate aim of the problem is to develop the methods, techniques and tools for hydrocarbon exploration in the arctic offshore areas which low accessiblity due to pack-ice most of the year. The North-East Greenland Shelf (NEGS) has been selected as target for the project.Presently, only limited seismic data acquisition and no drilling activities have been carried out in the NEGS area or in other offshore pack-ice areas with similar conditions.Two concepts for seismic surveys under ice appear to be most promising- Icebreaker towable system- Submarine seismic.A number of problems to be overcome are identified as subjects for a detailed conceptual study (e.g. navigation, streamer positioning, data quality etc..).The two systems are very different in the way to overcome the low accessibility in pack-ice, and probably the survey requirements (size of area, line distance and available time) will influence on which system to use.Several problems, however, are the same for the two concepts, since the streamer has to be towed under ice and in a sufficient depth to avoid collision with deep ice keels. The deep towing problems include- streamer positioning- data quality (ghosting from surface)- buoyancy control- development of seismic equipment, etc.It is recommended that the deep towing problems are carefully evaluated in connection with the problem concerning the seismic vessel in future parts of the PACKICE project.The scope of the project is to develop concepts for seismic exploration in arctic offshore areas with pack-ice cover.PHASE I CONCEPTUAL STUDY (start Janv. 1989)Based on the knowledge of the existing methods for seismic data acquisition, proposals for new techniques applicable for seismic exploration in pack-ice areas will be generated.The basis for the INNOVATIVE DEVELOPMENT will include the following system concepts :- surface operated seismic vessels- sub-surface operated seismic vessels- unmanned operated vessel remotely operated from a mother ship- seismic exploration from a very large drifting ice flow with a "permanently" mounted array of signal sources and transducers.The BASIC DESIGN PARAMETERS will include seismic data acquisition methods with requirements determined according to the data quality needed for the different types of seismic work.The PHYSICAL ENVIRONMENTAL STUDY includes identification, collection and post-processing (statistical analyses) of all environmental data relevant for the assessment of the feasibility and the operation of the study concepts.The most promising concepts will be studied for TECHNICAL FEASIBILITY including evaluation of data quality, evaluation of the noise compensating system and specification of the minimum requirements for the seismic data acquisition and auxiliary equipment.Each concept generated in the innovative stage will be considered as a total operational system including equipment for data acquisition, data communication, base facilties, manning and logistics.The system concepts will further be evaluated for the ENVIRONMENTAL IMPACT on the nature. A RISK ANALYSIS study on each considered concept will be performed in order to describe the risk to personnel, equipment and environment.PHASE II DETAILED CONCEPT DEVELOPMENTStarted 1991PHASE III DETAILED DESIGN, CONSTRUCTION AND TESTINGPlanned to start 1992.